The button in the first picture appears to be a circuit breaker.
I would not believe the panel until I used a good VOM to confirm the battery voltage. If I were troubleshooting I would disconnect the batteries from all loads and measure the voltage. I would then charge the batteries with a GOOD battery charger until full. I would then reconnect the battery to the system and look at the reading on the panel. I would then figure my next step from there.
At 11 volts where the lights very dim? Did the TV work at all.
